Globally aligned states and hydrodynamic traffic jams in confined active suspensions.pdf

《Globally aligned states and hydrodynamic traffic jams in confined active suspensions.pdf》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、GloballyalignedstatesandhydrodynamictracjamsinconnedactivesuspensionsAdrienLefauveandDavidSaintillanDepartmentofMechanicalScienceandEngineering,UniversityofIllinoisatUrbana-Champaign,Urbana,Illinois61801,USA(Dated:July26,2013)Stronglyconnedactiveliquidsaresubjecttouniquehydrody

2、namicinteractionsduetomomen-tumscreeningandlubricatedfrictionbytheconningwalls.Usingnumericalsimulations,wedemon-stratethat2Ddilutesuspensionsoffore-aftasymmetricpolarswimmersinaHele-Shawgeometrycanexhibitarichvarietyofnovelphasebehaviorsdependingonparticleshape,including:coher-en

3、tpolarizeddensitywaveswithglobalalignment,stationaryasters,persistentcounter-rotatingvortices,densityshocksandrarefactionwaves.Wealsoexplainthesephenomenausingalinearstabilityanalysisandanonlineartrac owmodel,bothderivedfromamean-eldkinetictheory.PACSnumbers:87.18.Hf,47.63.Gd,47.

4、57.E-,05.65.+bThespontaneousemergenceofcollectivemotion,large- owinducedbyitspermanentforcedipoleispartiallyscalecoherentpatternsandcomplexunsteady owsisascreenedbythewallsanddecaysrapidlyas1=r3ingenericfeatureofawidevarietyofsoftactivesystemsthefareld[27{29],whereristhedistancef

5、romthe[1{3],including:bacterialswarmsandsuspensions[4{particle,asopposedtotheusual1=r2decayintheab-6],reactivecolloidalsuspensions[7,8],cytoplasmicex-senceofconnement.Undertheseconditions,thefar-tracts[9],solutionsofbiologicallamentsandmotorpro-eld owassumestheHele-Shawformandca

6、nbemod-teins[10,11],andshakengranularmaterials[12,13].Ineledasatwo-dimensionalpotential ow[28]:u(r)=thesesystems,animmersedmicrostructure(suchasself-(h2=12)r(r),wherer=(x;y),isthedynamicvis-propelledparticlesorbiolament/motor-proteinassem-cosity,andfu;gdenotethegap-averagedve

7、locityandblies)convertsasourceofenergy(oftenchemical)intopressureelds.Asaparticlewiththickness.hlocatedmicrostructuralchangesthatcreateactivestressesandatpositionR(t)movesinanexternal owu(r;t)insuchcandrivecoherent owsonmesoscopiclengthscales.An-ageometry,thedisturbancevelocityiti

8、nducesisnowalyzinghowthein